Design of rubberized asphalt mixtures for noise and vibration damping layers

Traffic-induced vibrations challenge road authorities due to their harmful effects on humans and buildings. The use of rubberized binders seems to improve the damping properties of asphalt mixtures reducing the vibratory mechanism. However, a reliable design methodlacks definition. This work aism at designingtwo mixtures for damping layer prepared with large volumes of rubberized binder. The mixtures were prepared by increasing the binder content and maintaining the same Dust Proportion of an Open Grade mixture used as reference.Tensile strength, moisture susceptibility, stiffness, and phase angle, and damping ratio were measured in laboratory. The latter was used to otpize damping propertires.The mixtures show adequate tensile strength and, obviously, low moisture susceptibility. On the other hand, the increase in the binder content softens the mixtures. However, the reduction in stiffness is accompanied by an increase in damping ratio which indicates a higher energy dissipation under dynamic loadings.